我有 3 个不同的表余额、已收到、费用，其中包含以下数据。
收到表:
mysql> select * from received;
+-----+---------+-----------------+---------------------+
| rid | site_id | received_amount | receive_date |
+-----+---------+-----------------+---------------------+
| 1 | 1 | 500 | 2015-08-19 18:16:51 |
| 2 | 1 | 600 | 2015-08-19 18:16:52 |
| 3 | 1 | 500 | 2015-08-20 18:16:52 |
| 4 | 1 | 500 | 2015-08-19 18:16:52 |
+-----+---------+-----------------+---------------------+
餐 table 费用:
mysql> select * from expenses;
+-----+---------+----------------+---------------------+
| eid | site_id | expense_amount | expense_date |
+-----+---------+----------------+---------------------+
| 1 | 1 | 500 | 2015-08-19 18:17:11 |
+-----+---------+----------------+---------------------+
表余额:
mysql> select * from balance;
+----------------+---------+---------------+--------------+-----------------+-----------------+------+------+---------------------+
| transaction_id | site_id | account_title | particulars | opening_balance | closing_balance | rid | eid | transaction_date |
+----------------+---------+---------------+--------------+-----------------+-----------------+------+------+---------------------+
| 1 | 1 | test1 | test1 values | 0 | 500 | 1 | NULL | 2015-08-19 18:16:51 |
| 2 | 1 | test1 | test1 values | 500 | 1100 | 2 | NULL | 2015-08-19 18:16:52 |
| 3 | 1 | test1 | test1 values | 1100 | 1600 | 3 | NULL | 2015-08-20 18:16:52 |
| 4 | 1 | test1 | test1 values | 1100 | 1600 | 4 | NULL | 2015-08-19 18:16:52 |
| 5 | 1 | test1 | test1 values | 1600 | 1100 | NULL | 1 | 2015-08-19 18:17:11 |
+----------------+---------+---------------+--------------+-----------------+-----------------+------+------+---------------------+
我正在尝试使用以下查询将收到的金额和费用合并到余额表中，但不知何故我无法获得正确的方法来获取它。
select
b.transaction_id,
b.site_id,
b.account_title,
b.particulars,
b.opening_balance,
r.received_amount,
e.expense_amount,
b.closing_balance,
b.transaction_date
from
balance b
inner join received r
on b.site_id = r.site_id
inner join expenses e
on b.site_id = e.site_id
group by
b.transaction_id;
我正在尝试获取此输出
+----------------+---------+---------------+--------------+-----------------+-----------------+----------------+-----------------+---------------------+
| transaction_id | site_id | account_title | particulars | opening_balance | received_amount | expense_amount | closing_balance | transaction_date |
+----------------+---------+---------------+--------------+-----------------+-----------------+----------------+-----------------+---------------------+
| 1 | 1 | test1 | test1 values | 0 | 500 | NULL | 500 | 2015-08-19 18:16:51 |
| 2 | 1 | test1 | test1 values | 500 | 600 | NULL | 1100 | 2015-08-19 18:16:52 |
| 3 | 1 | test1 | test1 values | 1100 | 500 | NULL | 1600 | 2015-08-20 18:16:52 |
| 4 | 1 | test1 | test1 values | 1600 | NULL | 500 | 1100 | 2015-08-19 18:16:52 |
| 5 | 1 | test1 | test1 values | 1100 | 500 | NULL | 1600 | 2015-08-19 18:17:11 |
+----------------+---------+---------------+--------------+-----------------+-----------------+----------------+-----------------+---------------------+
最佳答案
你们有点接近了。您需要对收据和费用执行 LEFT-JOIN，而不是 INNER JOIN。由于您的“余额”表包含所有事务，因此它将驱动它在基础支持表中看到的条目。另外，不要只加入站点 ID，而只加入“rID”和“eID”，因为无论如何它们都是表上的主键。
无需按交易 ID 进行分组，因为它是余额表中的主键，并且给定 ID 只有一个条目。
select
b.transaction_id,
b.site_id,
b.account_title,
b.particulars,
b.opening_balance,
r.received_amount,
e.expense_amount,
b.closing_balance,
b.transaction_date
from
balance b
LEFT join received r
on b.rid = r.rid
AND b.site_id = r.site_id
LEFT join expenses e
on b.eid = e.eid
AND b.site_id = e.site_id
order by
b.site_id,
b.transaction_date
关于mysql - 超过 2 个表的内连接，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/32096935/